Electroreciprocal system



ELECTRORECIPROCAL SYSTEM Original Filed OGt. 22, 1936 I INV NTORATTORNEY Patented Mar. 14, 1944 UNITED, STATES FAT'ENT OFFICEELECTRORECIPROCAL SYSTEM Thomas}, Murphy, Stamford, Conn.

Original application October 22, 1936, Serial No. 106,935. Divided andthis application June 19, 1941, Serial No. 398,801

4 Claims. (Cl. 1'72'126) The invention relates to a-novel means ofelectrically exciting or energizing windings so *disposed or located,that a magnetic member operating therewith, may be caused to oscillateor vibrate at practically any velocity and amplitude.

This application is a division of my prior application, Serial #106,935filed October '22, "1936, and issued July 8, 1941, as Patent No.2,248,110.

A main feature of the invention is that a large number of reciprocatingdevices can be operated simultaneously from a central distributor.

It is an object of the invention to produce such a device, which issimple in construction and operation, and may be 'built as a unitaryassembly, and which may be operated by merely connecting it to a sourceof electrical supply.

Other objects and advantages will appear from the following descriptiontaken in connection with the accompanying drawing, forming a part ofthis specification, but it is distinctly understood that the drawing ismerely illustrative,

and various modifications may be employed without departing from theprinciple of the invention.

In the drawing, the figure is a diagrammatical View of the distributorand a reciprocating device to be actuated, together with the necessaryelectrical connections essential to and between the respective devices.

Broadly speaking the principle of the invention involves a plurality ofgaps between electrodes, connected to a source of alternating currentsupply. Means of successively causing a disruptive electrical dischargeacross the electrodes to render the gaps conductive. Further means ofconnecting the electrodes to windings of a translating device, saidwindings embracing the path of movement of a magnetic element, which iscaused to reciprocate or oscillate in step or some sub-multiple of theimpressed frequency of current supply.

Referring to the drawing, it will be seen that one end of each of thecoils l1, l8, H! and are connected by a lead'5l to one side of the A. C.supply indicated at' 52. The other end of each coil is connected to oneside of a spark gap through the leads a b, c, and d respectively, thecoil ll being connected to one side of the gap 53 while the other coilsI8, [9, and 20 are connected to one side of the gaps 54, 55 and 56respectively.

"The electrodes '51 and 58 of these gaps may be stationary members ofany suitable material, but they are preferably rollers made ofartificial graphite and arranged to rotate in opposite circuit andalsoto prevent rapid disintegration or undue heating of the electrodes andthus greatly increase their life. The electrodes 58 on the oppositesides of the gaps from the electrodes '51 (connected with the coils) areconnected to the opposite side of the A. C. supply 52 as indicated bythe lead 59.' The gaps are so proportioned that the voltage of the A. C.supply is insufiioient to initiate a flow of current across the gaps. Itwill thus be seen that the main circuit through each coil also includesa discharge gap.

Each gap is also in a secondary circuit which circuit includes arotating timer member 60 which is rotated at the proper synchronousspeed by a synchronous motor El so as to pass successively acrosscontacts 62, 63, 64 and 55. Contact 62 is connected by lead with thecoil side of the gap 55. The contact 63 is connected by lead 81 with thecorresponding side of the gap 56, and contacts 64 and 65 are connectedby leads 68 and 69 respectively with the correspond ing sides of thegaps 54' and 53 respectively. The electrodes 58 on opposite sides of thegaps are connected as shown bylead 1'0 with the rotating contact 60through a secondary coil H of a transformer across whcih is connected acondenser 12. The primary coil 13 of this transformer is connected withthe source of A. C. supply 52 as indicated through a non-inductiveresistance 14 across which is connected a condenser 15. This transformer13-11 builds up a sufficient voltage in the secondary circuit toinitiate a disruptive discharge across the various gaps in "successionas the contact member 6!) rotates'across the contacts 62 to 65, thisdischarge is oscillatory because of the condenser 12 which is chargedfrom the transformer. Immediately the disruptive discharge is initiatedacross one of the gaps this reduces the resistance in the main circuitthrough the corresponding coils l1, I8, l9 or 20 so that there is a flowacross the gap through this main circuit and the coil. As will be seenfrom the drawing each coil is shunted by a non-inductive relatively highresistance 16 which prolongs the duration of the disruptive dischargeacross the gap thus permitting the current to rise to the initial valuein the exciting windings I1, l8, 19 or 20' in whichever circuit the gaphappens tobe. Withoutthisnoninductive resistance shunting the windingthe duration of the discharge across the gap would not be sufilcient tobuild up the current in the coil to the desired value due to itsinductance.

With this resistance, however, which should be about 1,500 ohms for eachcoil for a 240 volt supply, the discharge is suificiently prolonged asindicated above to permit the current to rise to its full initial valuein the coil and thus give its maximum pull on the reciprocating element2|.

With the contact or timer bar 60 in the position shown in the drawing,it will be seen the disruptive discharge is across the gap 53 and thecoil 11 is energized bringing the reciprocating element H to the righthand or fully retracted position. As the member 6|] is further rotatedto the right or clockwise as indicated, its upper or right hand armmoves away from the contact 65 opening the circuit through the gap 53.At the same time its lower or left hand arm moves to the contact 62 thusclosing the circuit through the gap 55 and energizing the coil I9 anddeenergizing the coil [1. This immediately pulls the hammer II to theleft and as it passes through the coil l9 the element 60 moves from thecontact 62 to contact 63, thus closing the circuit across the gap 56 andenergizing the coil 20 and deenergizing the coil l9. This coil 20 stillfurther accelerates and increases the speed of movement of thereciprocating member 2| so that it may impart a maximum blow.

Continued movement of the contact 60 carries it to the contact 64 whichcloses the circuit across the gap 54 energizing the coil [8 anddeenergiz ing coil 20'. This therefore gives a pull on the reciprocatingmember in the opposite direction and. as it passes through coil l8member 60 moves to contact 65 closing the circuit across the gap 53 toagain energize the coil [1 to draw the reciprocating member to its fullretracted position. The synchronous timer or timing bar 60 perfectlyrotates at 900 R. P. M. on a 60 cycle circuit to successively dischargethe condenser 12 across the graphite gaps in the order indicated. In theprocess described the current will flow in the energizing coils I1, l8,l9 and 20 progressively and will reciprocate the hammer member 2|rapidly back and forth. It is preferred that the alternate coils l1, l8,l9 and 20 be wound in the opposite sense, that is, if coil I1 is minusthe coil l8 would be plus, the coil l9 minus, and the coil 20 plus. Withthis arrangement there is no reversing of the flux in the magnetic coresor poles l4 and IE, or through the hardened moving element 2|, andtherefore no hysteresis loss. It will be seen in this instance that ifcoil l1 energizes pole la on its right as south then pole l5b would benorth, and then if coil IB is reversed, when it is energized pole l5bwould be still north and pole l5 south and so on. However, they are notnecessarily so arranged. The reciprocating element 2| i reciprocated ata frequency one-half that of the fundamental of the A. C. current. Asthe magnetic flux in the moving element 2| is not reversed it is notnecessary to make this element of a laminated structure.

Having thus set forth the nature of my invention, what I claim is:

1. In combination, a reciprocable element, a plurality of windingsembracing the path of the element and placed in succession along thispath, adjacent windings being wound in opposite senses, a main circuit,means for connecting said circuit with a source of alternating current,said circuit comprising a plurality of parallel paths with one of saidwindings in each path, a discharge gap in each path, said source beingof insufficient potential to initiate a flow of current across the gaps,means for disruptively discharging a condenser across the gaps insuccession to permit current from said alternating current source toflow in the respective circuits in succession to reciprocate theelement, and a non-inductive resistance shunting the respective windingsto permit an initial current flow in the respective paths through saiddischarge and prolong the discharge sufficiently to permit current fromthe alternating current supply to flow through the windings.

2. In combination, a main circuit, means for connecting said circuitwith a source of electric energy, said circuit including an inductiveWinding and a discharge gap in series with said source, said circuithaving insufficient potential to initiate a flow of current through thegap, means for forming a momentary arc across said gap by the disruptivedischarge of a condenser to permit flow of current from said sourceacross the gap, and a relatively high non-inductive resistance shuntingsaid inductive winding to permit sufllcient initial current to flow inthe main circuit to prolong the discharge sufficiently to permit currentfrom the supply to flow through the winding.

3. In combination, a main circuit, means for connecting said circuitwith a source of alternating current, said circuit including anenergizing winding and a discharge gap, said circuit having insufficientpotential to initiate a flow of current across said gap, an auxiliarycircuit including said gap, means in said auxiliary circuit to supply apotential sufiicient to initiate a disruptive discharge across said gap,a non-inductive resistance shunting said winding to permit an initialcurrent flow in the main circuit through said discharge and prolong thedischarge suiliciently to permit current from the alternating currentsupply to flow through the winding, and means for closing the auxiliarycircuit across the gap in synchronism with the alternations of thecurrent in the main circuit.

4. In combination, a reciprocating element, a plurality of windingsembracing and arranged along the path of the element with adjacentwindings being wound in opposite senses, a main circuit, means forconnecting said circuit with a source of alternating current, saidcircuit comprising a plurality of parallel paths with one of saidwindings in each path, a discharge gap in each path, said source beingof insuificient potential to initiate a flow of current across the gaps,an auxiliary circuit having branches in each of which is one of saidgaps, said auxiliary circuit being of sufficiently high potential toinitiate a disruptive discharge across said gaps, a noninductiveresistance shunting the winding in each path to permit an initialcurrent flow in the respective paths through said discharge and prolongthe discharge sufiiciently to permit current from the alternatingcurrent supply to flow through the windings, and means in the auxiliarycircuit for causing a disruptive discharge of a condenser across saidgaps in succession and in synchronism with the current in the maincircuit to energize said windings in succession and reciprocate theelement.

THOMAS J. MURPHY.

